Converter gearing

ABSTRACT

The invention relates to a converter gearing, comprising a gear rim ( 7 ), which is connected to the pivoting axis ( 6 ) of a converter box, said gear rim being engaged with at least one drive pinion ( 8 ) of the converter gearing ( 9 ) and at least one locking device, which can be pivoted to engage with and be disengaged from the toothed gearing of the gear rim, ( 7 ) in the form of a locking arm ( 12 ) that is positioned on a horizontal shaft ( 10 ) and configured with toothed gearing ( 11 ). The aim of the invention is to improve said locking device. To achieve this, the shaft ( 10 ) of the locking arm ( 12 ) is mounted in at least one terminal bearing ( 13, 13 ′) and the locking arm ( 12 ) can be engaged with and disengaged from the toothed gearing of the gear rim ( 7 ) in a non-positive manner, preferably by means of active force elements ( 14, 14 ′) in its end regions. In addition, the shaft ( 10 ) of the locking arm ( 12 ) is mounted in the housing of the converter gearing ( 9 ) by means of two excentric bushes ( 4, 5 ), which rotate freely within one another, at each of its ends. The mounting is configured in such a way, that by the independent rotation of the same, an ideal mutual engagement position of the two interacting toothed gearing regions of the locking device ( 12 ) and the gear rim ( 7 ) can be set.

The invention concerns converter gearing, which comprises a gear rim,which is connected to the axis of rotation of a converter vessel andengages at least one drive pinion of the converter gearing, and at leastone locking device, which can be swung in and out to engage with ordisengage from the teeth of the gear rim and has the form of a lockingarm that is configured with teeth and is mounted on a horizontal shaft.

Converter gears are subjected to high and variable torques during theoxygen-blowing operation. These torques usually lead to extreme loadsper unit surface area and thus to excessive wear of the teeth.

It is well known that the harmful loads can be significantly reduced bythe use of a locking arm. The terminal toothing of the locking arm forlocking engagement in the teeth of the gear rim on the converter vesselcorresponds as a “negative form” to about 5 to 6 tooth spaces of thedriven gear. The load thereby evenly distributed to a region of thetoothing results in a significant reduction of the surface pressure onthe toothing and thus a reduction of the wear caused by the surfacepressure.

A disadvantage of this design is the required setting precision of thelocking lever and its bearing, especially when two independent lockinglevers are installed. This means that even small deviations from theideal engagement position can lead to extremely high forces and stressesand thus to faster wear of the gear rim and the locking arm teeth.

To avoid these consequences, use was made of the measure of machiningthe housing and locking arm bore together. To do this, it is necessaryto preassemble the gear rim and locking arm in their optimum position inthe housing, then to fasten them in place and, finally, to machine themtogether.

This not only results in high production costs, but also has the furtherdisadvantage that subsequent replacement or readjustment of the lockingarm is not possible due to the special machining sequence.

The document EP 1 022 482 A1 describes a device for locking an elementof a kinematic chain on a casting ladle, which comprises a part with anarea of relief-like elevations and depressions provided on itsperiphery, which are complementary to areas with relief-like depressionsand elevations on the element to be locked, and a device, which isinstalled at the end of a locking arm, for moving the part between apassive position “disengaged” from the element to be locked and anactive position, in which the elevated and depressed areas of theelement and the part penetrate each other to lock the element in apredetermined position. Indicating devices for the element in thepredetermined position with respect to its elevated and depressed areasand devices for indicating the position of the locking arm are alsoprovided.

Proceeding from the prior art described above, the objective of theinvention is to produce converter gearing of the type specified in theintroductory clause of Claim 1 with an improved design and to design itwith means for adjusting an ideal engagement position of the toothingbetween drive pinion and gear rim in such a way that the optimum settingprecision of the locking lever relative to the gear rim of the gearingcan be readjusted at any time independently of the production of theseelements.

In accordance with the invention, to achieve this objective in convertergearing of the type described above, it is proposed that the shaft ofthe locking arm is supported in at least one terminal bearing, that thelocking arm can be nonpositively engaged with the teeth of the gear rimand can be disengaged from the teeth of the gear rim by means of activeforce elements, and that the shaft of the locking arm is supported inthe housing of the converter gearing by two eccentric bushes, whichrotate freely, one within the other, at each end of the shaft, in such away that an ideal mutual engagement position of the two interactingtoothed regions of the locking device and the gear rim can be set byindependent rotation of the eccentric bushes.

The design of the support of the locking arm in accordance with theinvention results in the great advantage that optimum adjustability ofthe backlash of the drive toothing of the gearing can be achieved at anytime and independently of its production, and/or the backlash can bereadjusted. This results in an even load distribution in the region ofthe locking teeth with about 5 to 6 tooth spaces of the region ofengagement of the driven gear with drastically reduced load per unitsurface area of the tooth flanks. The wear of the gear wheels of thegearing is reduced accordingly.

Advantageous refinements of the mounting method of the invention arespecified in the dependent claims.

A method of adjusting a low-backlash mounting of the shaft of thelocking arm of a design in accordance with the invention isdistinguished by the fact that an optimum engagement of the toothedregion of the locking device with the gear rim is first set by rotationof the eccentric bushes of the shaft with the clamping elementsreleased, and that the clamping elements of the two terminal bearingsare then brought into a low-backlash bearing state by expansion, and theeccentric bushes are locked in the setting they have then reached.

Further details, features, and advantages of the invention are revealedby the following explanation of several embodiments, which are shownschematically in the drawings.

FIG. 1 shows converter gearing in a side view.

FIG. 2 shows the mounting of the shaft of a locking arm in eccentricbushes in the sectional plane indicated by I-I in FIG. 1.

FIG. 3 shows an axial cross section of a pair of eccentric bushesmounted one inside the other in an eccentric position.

FIG. 4 shows various eccentric positions of eccentric bushes mounted oneinside the other.

FIG. 1 shows a side view of converter gearing, which comprises a gearrim 7, which is connected to the axis of rotation 6 of a convertervessel (not shown) and engages at least one drive pinion 8 of theconverter gearing 9, and at least one locking device, which can be swungin or out to engage with or disengage from the teeth of the gear rim 7and has the form of a locking arm 12, which is mounted on a horizontalshaft 10, is configured with teeth 11 in its end region, and isrotatably supported.

The locking arm 12 is supported with the shaft 10 in at least oneterminal bearing 13, 13′ and can be nonpositively engaged with the teethof the gear rim 7 or disengaged from the teeth of the gear rim 7 bymeans of active force elements 14, 14′, e.g., hydraulic cylinders, whichpreferably act on its end regions. The shaft 10 of the locking arm 12 issupported in the housing of the converter gearing 9 by two eccentricbushes 4, 5, which rotate freely, one within the other, at each end ofthe shaft 10. An ideal mutual engagement position of the two interactingtoothed regions of the locking device 12 and the gear rim 7 can be setby independent rotation of the eccentric bushes 4, 5.

A clamping element 16, 16′ for adjusting a low-backlash bearing 13, 13′is associated with each of the eccentric bushes 4, 5 and the bores 18,18′ of the converter gearing 9 which hold the eccentric bushes. This canbe accomplished if, for example, the clamping element 16 is a clampingbush that can be expanded in its inside and outside diameter by means ofaxial keys 17.

The adjustment of a backlash-free bearing 13, 13′ of the shaft 10 of alocking arm 12 of the locking device and the adjustment of optimumengagement of the toothed region of the locking arm 12 with the gear rim7 of the converter gearing 9 are accomplished by rotation of theeccentric bushes 4, 5 with the clamping elements 16 released. Theclamping elements 16 of the two terminal bearings 13, 13′ are thenbrought into a low-backlash bearing state by expansion, and theeccentric bushes 4, 5 are locked in their setting.

FIGS. 3 to 6 show different states of the penetration of the outereccentric bushes 5 by the inner eccentric bushes 4.

In these drawings, the centers of rotation of the outer bushes 5 arelabeled with the reference number “1” the centers of rotation of theinner bushes 4 are labeled with the reference number “2”, and thecenters of the bores in the inner bushes 4 are labeled with thereference number “3”.

FIG. 3 shows the so-called zero position, in which the eccentricities ofthe two bushes offset each other. The eccentricity of a bush is thuscharacterized by the indicated distance “5”.

1. Converter gearing, which comprises a gear rim (7), which is connectedto the axis of rotation (6) of a converter vessel and engages at leastone drive pinion (8) of the converter gearing (9), and at least onelocking device, which can be swung in or out to engage with or disengagefrom the teeth of the gear rim (7) and has the form of a locking arm(12), which is mounted on a horizontal shaft (10) and is configured withteeth (11), wherein the shaft (10) is supported in a terminal bearing(13, 13′), the locking arm (12) can be nonpositively engaged with ordisengaged from the teeth (11) by active force elements, e.g., hydrauliccylinders (14, 14′), and the shaft (10) is supported in the housing ofthe converter gearing (9) by two eccentric bushes (4, 5), which rotatefreely, one within the other, at each end of the shaft, in such a waythat an ideal engagement position of the interacting toothed regions ofthe locking device (12) and the gear rim (7) can be set by independentrotation of the eccentric bushes, and a clamping element (16, 16′) foradjusting a low-backlash bearing (13) is associated with each of theeccentric bushes (4, 5) and the bores (18, 18′) which hold the eccentricbushes, wherein the clamping element (16) is a clamping bush (17) thatcan be expanded in its inside and outside diameter by means of axialkeys (17′).
 2. Method of adjusting a low-backlash bearing of the shaft(10) of a locking arm (12) of the locking device on the convertergearing (9) for the purpose of optimum engagement of the toothed regionof the locking device (12), characterized by the fact that wherein anoptimum engagement of the toothed region of the locking device is firstset by rotation of the eccentric bushes (4, 5) with the clampingelements (16) of the shaft bearing released, and that the clampingelements (16) of the terminal bearings (13, 13′) are then brought into alow-backlash bearing state by expansion, and the eccentric bushes (4, 5)are locked in their setting.